Misc: which community has the highest level of rh-negative blood in the world?

Questions

on august 26 1990, after finishing an encore jam featuring eric clapton, buddy guy and robert cray, whose helicopter crashed on his way from wisconsin to chicago?

on porter waggoner's tv show, who was his first singing partner?

on their first studio release in seven years, who released the album 'in the dark'?

which one man band released the album 'mellow gold'?

when did it snow in the sahara desert?